The present invention relates to a vacuum-type brake booster device for automotive use. More particularly, the invention relates to such a vacuum-type brake booster device which can easily be mounted, such as during the manufacture and repair of the vehicle, and which provides reduced interference with the mounting of other components of the vehicle.
A vacuum-type brake booster device is generally mounted on the front surface of the fire wall of the vehicle, behind the wheel well and adjacent the rear end of the engine. The brake master cylinder is mounted on the forward end of the booster. Conventionally, it has been difficult to mount the booster device and master cylinder due to interference with other components of the vehicle, such as suspension components which are mounted at the adjacent wheel well.
To overcome this difficulty, vacuum-type brake boosters have been proposed in which the shell or housing of the booster is made noncircular in cross section to thereby prevent side portions of the shell from interfering with the mounting of the device and the mounting of other components. Examples of such devices are shown in U.S. Pat. No. 2,896,586, issued July 28, 1959 to Ayers, Jr., and U.S. Pat. No. 4,434,707, issued Mar. 6, 1984 to Takeuchi et al. Although some advantages may be attained using such an approach, nevertheless, such vacuum-type brake boosters suffer from a drawback in that the effective pressure receiving area of the booster is excessively great.